Clean Water, Little Fuss: PATH and Cascade Designs Bring Purifiers to Africa

7/14/09

Taking a sip from a kitchen faucet rarely causes someone’s heart to pound or adrenaline to flow, but for millions around the world, drinking the local water is just another version of Russian roulette. With every mouthful of water, people in developing countries imbibe bacteria and viruses that can and often do cause lethal diseases, especially in children. According to the World Health Organization, diarrheal diseases from impure water kill 4,100 children every day.

Seattle-based PATH is one of many organizations that seek to alleviate the poor health conditions found around the world. Distributing vaccines, educating about AIDS, and improving general healthcare in underserved parts of the world are all part of PATH’s mandate. In 2008, using a grant from the Laird Norton Family Foundation, PATH began exploring ways of using commercial water-purifying technology for small villages and towns. “We did a broad outreach and looked at different ideas,” said Kendra Chappell, manager of the pure water project at PATH. Eventually, PATH decided to partner with Seattle-based Cascade Designs, a company that makes camping equipment. Cascade, with money from the U.S. Defense Department, had developed a cheap and clean method of water purification through a process called electro-chlorination. “It was a good match,” Chappell said.

The purifier created by Cascade uses electricity to create chlorine, which quickly kills parasites, bacteria, and viruses. Salt is added to the unclean water, and then the mixture is zapped by a few volts of electricity. (The electricity breaks the salt into its component elements of sodium and chlorine.) “It turns brine into a powerful disinfectant,” said Laura McLaughlin, an environmental engineer and project manager at Cascade. The system carefully measures the amount of chlorine generated, so that only enough is made to clean the water—not so much that the water becomes undrinkable. “Our system is geared toward providing the right dose,” McLaughlin said.

Other methods of water purification are not usually as thorough or effective. Water filters cannot keep out viruses because they are much smaller than bacteria, and even iodine cannot kill all waterborne disease agents. Cascade’s technology is also remarkably friendly to the environment; it uses no toxic chemicals and very little energy.

Working together, PATH and Cascade scaled up the purification system. “It was a team effort all the way through,” Chappell said. The prototype could clean 20 liters of water at a time, a process that takes only two minutes. In December of 2008, the prototype was taken to Korogocho, Kenya, a slum area in Nairobi, and given to the main community organization, the Redeemed Gospel Church. The program members stayed long enough to train residents how to use the prototype, although it is fairly straightforward. “All that you do is push a button,” McLaughlin said. The unit requires just batteries, water, and salt, enabling the poor community to clean a lot of water quickly and easily.

Korogocho was chosen not just because of the state of its water resources, but because PATH has an office nearby to help monitor the usage and effectiveness of the prototype. The water used in the system comes from Nairobi, which provides some water treatment, but the city water isn’t always drinkable. And when water is unavailable from the city, the village can now buy water from merchants, even if it is unclean, since they can clean it themselves. “They can even sell water to outsiders,” Chappell said.

Last month, after further refinement, the PATH and Cascade team returned to the village to deliver a new prototype and to get feedback on the previous model. Funding for the new refinements came from the Lemelson Foundation. The villagers were generally pleased with the system, McLaughlin said, and had suggestions mainly on how to improve the looks of the device.

The partnership’s next step is to try out the prototypes at multiple locations and then, if successful, sell the systems to the proper organizations and groups. All the profits from the purifiers will go to Cascade, but the partnership with PATH with not end there. “This program is the base of the pyramid,” McLaughlin said. Related projects include testing water treatment storage over time and trying to simulate different types of dirty water in order to make better purifiers. There are just two types of EPA test water, “kind of clean and extremely dirty,” Chappell said. More realistic test water types for lab use are important for future research, she added.

Eric Hal Schwartz was an intern in Xconomy's Seattle office. Follow @

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